The tombs of Muslim soldiers who served in the French army during World War I were desecrated on Sunday night in a cemetery in the north of France. The attack took place on the eve of Eid al-Adha, the Festival of Sacrifice, one of the most important holidays in the Islamic calendar, when many Muslims visit the graves of loved ones.

Notre-Dame-de-Lorette cemetery, the country’s largest military cemetery, houses the remains of about 40,000 war veterans, including 575 Muslim headstones which are grouped together and turned toward Mecca. An estimated 500 of these were found spray-painted with either swastikas or with letters spelling out Islamophobic graffiti and Nazi slogans such as “Heil Hitler.”

It is the third time in the past two years that the Muslim section of the cemetery has been targeted. In April, vandals desecrated 148 Muslim graves, hung a pig’s head from one tombstone, and graffitied slogans insulting France’s Muslim justice minister. Two men are awaiting trial over this incident, but deny the charges. A year earlier, neo-Nazi vandals painted swastikas on 52 of the cemetery’s Muslim graves. Two youths aged 18 and 21 were jailed for one year over that attack.

French President Nicolas Sarkozy condemned Sunday’s attack as an “abject and revolting act” which demonstrates “repugnant racism against France’s Muslim community” and insults the memory of all World War I combatants. He called for a swift inquiry. An investigation is underway to find the culprits, with around 100 French police at the site to gather evidence.

This French Muslim blogger reacted with anger: “The choice of day (Eid festival) and of location (a military cemetery) signals a double provocation against the memory of the deceased and their loved ones, and against the French republic for whom these soldiers sacrificed their lives…. This unfortunate series of Islamophobic desecrations is evidence of the ineffectiveness of the government’s response to this new form of anti-Arab racism.”

Hundreds of thousands of Muslim soldiers from France’s African colonies fought during World War I and tens of thousands were killed.

WIDE ANGLE’s Young, Muslim, and Frenchexplores tensions between secular and Islamic values in France, home to Europe’s biggest Muslim community.